scholarly journals Η επίδραση της ερυθροποιητίνης στην οξεία νεφρική ισχαιμία

2014 ◽  
Author(s):  
Κυριακή Ξανθοπούλου
Keyword(s):  
Rt Pcr ◽  
Cyt C ◽  
Cox 2 ◽  
Fasl Mrna

Η επίδραση της ερυθροποιητίνης στην οξεία νεφρική ισχαιμία. Πειραματική μελέτη σε επίμυες.Η ερυθροποιητίνη (ΕΡΟ) εμφανίζει πλειοτροπικές ιδιότητες. Σκοπός της μελέτης ήταν η διερεύνηση της επίδρασης της ΕΡΟ στην οξεία νεφρική ισχαιμία/επαναιμάτωση (ΝΙ/Ε). Άρρενες επίμυες Wistar υποβλήθηκαν σε αμφοτερόπλευρη NΙ/Ε 45 λεπτών. Χωρίστηκαν τυχαία στις ομάδες Ι/Ε (n=34) και EPΟ (χορήγηση 500 IU/kg, i.p, 20 λεπτά πριν την ισχαιμία, n=36). Σε κάθε ομάδα ορίστηκαν τρεις υποομάδες, στις οποίες η επαναιμάτωση ολοκληρώθηκε στις 6, 24 και 48 ώρες αντίστοιχα. Χειρουργηθέντες επίμυες που δεν υποβλήθηκαν σε ισχαιμία αποτέλεσαν τους μάρτυρες (n=10). Η νεφρική βλάβη εκτιμήθηκε με βιοχημικούς δείκτες (ουρία και κρεατινίνη) και διαβάθμιση της έκτασης της σωληναριακής βλάβης. Η έκφραση των Cyt c, nNOS, iNOS, eNOS και COX-2 μελετήθηκε ανοσοϊστοχημικά και των Fas/FasL, nNOS και Cyt c με RT-PCR. Η ΝΙ/Ε προκάλεσε επιδείνωση των βιοχημικών δεικτών και εγκατάσταση ιστολογικών αλλοιώσεων. Στην ομάδα EPΟ διαπιστώθηκαν χαμηλότερες τιμές βιοχημικών δεικτών και μικρότερης έκτασης σωληναριακή βλάβη (p<0,05). mRNA των Fas/FasL και Cyt c απομονώθηκαν από τους φυσιολογικούς νεφρούς. Το Fas/FasL mRNA δεν μεταβλήθηκε στις δύο ομάδες. Η ΝΙ/Ε προκάλεσε αύξηση της γονιδιακής και πρωτεϊνικής έκφρασης του Cyt c (κυρίως στις 48 και στις 6 ώρες αντίστοιχα). Η ΕΡΟ μείωσε την γονιδιακή έκφραση του Cyt c στις 48 ώρες, ενώ περιόρισε την πρωτεϊνική έκφρασή του κυρίως στις 6 ώρες. Η έκφραση της nNOS στους φυσιολογικούς νεφρούς μειώθηκε σημαντικά στις 6 ώρες επαναιμάτωσης, ενώ στη συνέχεια έτεινε να αποκατασταθεί. Η ΕΡΟ διατήρησε την έκφραση της nNOS στις 6 ώρες στα επίπεδα των μαρτύρων. Περιορισμένη έκφραση της iNOS παρατηρείται στους φυσιολογικούς νεφρούς. Η iNOS ανοσοαντίδραση αυξήθηκε σταδιακά από τις 6 στις 24 ώρες επαναιμάτωσης στα σωληνάρια και αγγεία. Η ΕΡΟ περιόρισε την ένταση της iNOS έκφρασης μεταϊσχαιμικά. Η eNOS εκφράζεται στα φυσιολογικά σωληνάρια και αγγεία. Επαγωγή της σημειώθηκε στις 6 και 24 ώρες στην ομάδα Ι/Ε, ενώ στην ΕΡΟ ήταν εμφανής μόνο στις 24 και στους ιστούς με μεγάλη βλάβη. Η COX-2 εκφράζεται φυσιολογικά σε πυκνές κηλίδες και σωληνάρια. Επαγωγή της σημειώθηκε στις 6 ώρες επαναιμάτωσης, η οποία στη συνέχεια υποχώρησε. Η ΕΡΟ περιόρισε αυτήν την επαγωγική αιχμή της COX-2 των 6 ωρών. Συμπερασματικά, η χορήγηση της ΕΡΟ ήταν νεφροπροστατευτική. Η ΝΙ/Ε και η ΕΡΟ δεν επηρέασαν την έκφραση των Fas/FasL. Η πρώιμη επαγωγή του Cyt c υποδηλώνει συμμετοχή του στην μεταγενέστερη εγκατάσταση βλάβης. Η ευεργετική δράση της ΕΡΟ εκδηλώνεται μέσω του ενδογενούς αποπτωτικού μονοπατιού. Η nNOS συμμετέχει στη φυσιολογική νεφρική λειτουργία. Η πρώιμη εξασθένιση της μετά την ισχαιμία, εκτός από επακόλουθο της βλάβης, είναι πιθανά άμεσα επιζήμια. Η επαγωγική δράση της ΕΡΟ στην nNOS συσχετίζεται με αυξημένο αριθμό βιώσιμων σωληναρίων. Η μεταϊσχαιμική επαγωγή της iNOS συνδέθηκε με την εγκατάσταση σωληναριακής βλάβης. Η εξασθένιση της iNOS από την ΕΡΟ είναι αποτέλεσμα των αντιφλεγμονωδών και αντιοξειδωτικών ιδιοτήτων της. Η αύξηση της eNOS στη ΝΙ/Ε υποχώρησε μετά την εγκατάσταση σοβαρής βλάβης. Η δράση της ΕΡΟ δεν συσχετίζεται άμεσα με την eNOS. Η COX-2 συμμετέχει στους ομοιοστατικούς νεφρικούς μηχανισμούς. Η επαγωγή της στη ΝΙ/Ε ερμηνεύεται ως περαιτέρω ενεργοποίηση αυτών των μηχανισμών ή/και ως πυροδότηση φλεγμονής. Η ευεργετική δράση της ΕΡΟ περιορίζει την κινητοποίηση των μηχανισμών ομοιόστασης ή/και τον επιβλαβή ρόλο της COX-2.

scholarly journals Dose-dependent immune response in milk cells and mammary tissue after intramammary administration of lipopolysaccharide in dairy cows

2008 ◽  
Vol 52 (No. 6) ◽  
pp. 231-244 ◽  
Author(s):  
C. Werner-Misof ◽  
M.W. Pfaffl ◽  
R.M. Bruckmaier
Keyword(s):  
Immune Response ◽  
Mrna Expression ◽  
Real Time ◽  
Polymorphonuclear Neutrophils ◽  
Mammary Tissue ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Lps Challenge ◽  
Cell Counts ◽  
Cox 2

The immune response in milk cells and the status of mammary tight junctions (TJ) in response to intramammary (IM) infusion of different doses of <i>Escherichia col</i>i lipopolysaccharide (LPS) was investigated. <i>Experiment I</i>: Seven German Braunvieh cows were IM infused into one quarter with 1 &mu;g (LPS-1) and 3 &mu;g (LPS-3) of LPS, respectively, and the contralateral control quarter with saline (9 g/l; C). Milk samples were taken immediately before and 12, 24, 36, 48, 60, 84 and 108 h after infusion and analysed for somatic cell counts (SCC), lactose, sodium (Na) and chloride (Cl) ions, and electrical conductivity (EC). Milk cell mRNA expression of various inflammatory factors was quantified by real-time RT-PCR. Blood samples were taken immediately after milking for the analysis of leukocytes (WBC), polymorphonuclear neutrophils (PMN), Na and Cl. Milk SCC, lactose, Na, Cl and EC did not differ significantly between LPS-1 and C quarters after the challenge. In LPS-3 quarters SCC levels increased within the first 12 h, reached peak levels between 12 and 36 h (<i>P</i> &le; 0.001) and decreased (<i>P</i> &le; 0.05) thereafter to reach baseline at 108 hours. Lactose in LPS-3 quarters decreased (<i>P</i> &le; 0.05) to a minimum at 24 h and increased slightly thereafter while EC, Na, and Cl increased transiently in response to LPS-3. WBC and PMN levels in both groups decreased numerically within 24 h after LPS administration. In LPS-1, WBC at 24, 48 and 108 h were significantly lower whereas in LPS-3 they were significantly higher than at time 0. TNF&alpha;-mRNA expression in both groups did not change in response to IM LPS-challenge. IL-1&beta;-mRNA expression at 12, 24 and 36 h in LPS-1 quarters increased significantly as compared to time 0. In LPS-3 quarters the mRNA expression values of all tested ILs increased significantly as compared to time 0 within 12 h after LPS-challenge. IL-1&beta;-mRNA expression decreased (<i>P</i> &le; 0.05) at 48 and 84 h in LPS quarters. IL-8 mRNA was significantly decreased at 84 h after challenge in LPS-3 quarters. COX-2-mRNA expression in LPS-1 quarters decreased significantly as compared to time 0 at 48, 84 and 108 h, with a minimum at 84 h (<i>P</i> &le; 0.05). In LPS-3 quarters COX-2-mRNA levels increased (<i>P</i> &le; 0.05) within 48 h after the LPS-challenge. <i>Experiment II</i>: Six cows (5 German Braunvieh, 1 Brown Swiss) were injected in one quarter with 100 &mu;g LPS and in the contralateral quarter with saline (9 g/l; C). Mammary biopsy samples of both quarters were taken immediately before and at 3, 6, 9 and 12 h after infusion and mRNA expression of TJ proteins occludin (OCLN) and zonula occludens (ZO-) 1, 2 and 3 were quantified by real-time RT-PCR. OCLN-mRNA expression did not change in response to the IM infusion while that of ZO-1, ZO-2 and ZO-3 decreased significantly within six hours. In conclusion, a dose of 1 &mu;g LPS did not initiate a immune response in the mammary gland. Furthermore the dose of 100 &mu;g of LPS enhanced TJ permeability by reducing TJ plaque proteins density.

scholarly journals Inhibition of nNOS expression in the macula densa by COX-2-derived prostaglandin E2

2004 ◽  
Vol 287 (1) ◽  
pp. F152-F159 ◽  
Author(s):  
Alex Paliege ◽  
Diane Mizel ◽  
Carmen Medina ◽  
Anita Pasumarthy ◽  
Yuning G. Huang ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Mrna Expression ◽  
Real Time ◽  
Plasma Renin ◽  
Macula Densa ◽  
Renin Secretion ◽  
Renin Activity ◽  
Rt Pcr ◽  
Cox 2 ◽  
Nnos Expression

It is well established that cyclooxygenase-2 (COX-2) and the neuronal form of nitric oxide synthase (nNOS) are coexpressed in macula densa cells and that the expression of both enzymes is stimulated in a number of high-renin states. To further explore the role of nNOS and COX-2 in renin secretion, we determined plasma renin activity in mice deficient in nNOS or COX-2. Plasma renin activity was significantly reduced in nNOS −/− mice on a mixed genetic background and in COX-2 −/− mice on either BALB/c or C57/BL6 congenic backgrounds. In additional studies, we accumulated evidence to show an inhibitory influence of PGE2 on nNOS expression. In a cultured macula densa cell line, PGE2 significantly reduced nNOS mRNA expression, as quantified by real-time RT-PCR. In COX-2 −/− mice, nNOS mRNA expression in the kidney, determined by real-time RT-PCR, was upregulated throughout the postnatal periods, ranging from postnatal day ( PND) 3 to PND 60. The induction of nNOS protein expression and NOS activity in COX-2 −/− mice was localized to macula densa cells using immunohistochemistry and NADPH-diaphorase staining methods, respectively. Therefore, these findings reveal that the absence of either COX-2 or nNOS is associated with suppressed renin secretion. Furthermore, the inhibitory effect of PGE2 on nNOS mRNA expression indicates a novel interaction between NO and prostaglandin-mediated pathways of renin regulation.

scholarly journals Prostaglandin E2-synthesizing enzymes in fever: differential transcriptional regulation

2002 ◽  
Vol 283 (5) ◽  
pp. R1104-R1117 ◽  
Author(s):  
Andrei I. Ivanov ◽  
Ralph S. Pero ◽  
Adrienne C. Scheck ◽  
Andrej A. Romanovsky
Keyword(s):  
De Novo ◽  
Phase Iii ◽  
Rt Pcr ◽  
Febrile Response ◽  
Major Mechanism ◽  
High Magnitude ◽  
Cox 2 ◽  
Wistar Kyoto ◽  
The Brain ◽  
Cox 1

The febrile response to lipopolysaccharide (LPS) consists of three phases ( phases I–III), all requiring de novo synthesis of prostaglandin (PG) E2. The major mechanism for activation of PGE2-synthesizing enzymes is transcriptional upregulation. The triphasic febrile response of Wistar-Kyoto rats to intravenous LPS (50 μg/kg) was studied. Using real-time RT-PCR, the expression of seven PGE2-synthesizing enzymes in the LPS-processing organs (liver and lungs) and the brain “febrigenic center” (hypothalamus) was quantified. Phase I involved transcriptional upregulation of the functionally coupled cyclooxygenase (COX)-2 and microsomal (m) PGE synthase (PGES) in the liver and lungs. Phase II entailed robust upregulation of all enzymes of the major inflammatory pathway, i.e., secretory (s) phospholipase (PL) A2-IIA → COX-2 → mPGES, in both the periphery and brain. Phase III was accompanied by the induction of cytosolic (c) PLA2-α in the hypothalamus, further upregulation of sPLA2-IIA and mPGES in the hypothalamus and liver, and a decrease in the expression of COX-1 and COX-2 in all tissues studied. Neither sPLA2-V nor cPGES was induced by LPS. The high magnitude of upregulation of mPGES and sPLA2-IIA (1,257-fold and 133-fold, respectively) makes these enzymes attractive targets for anti-inflammatory therapy.

Combination Of Indoleamine 2,3-Dioxygenase Inhibitor and Cytotoxic Agents Is a Novel Therapeutic Option For Non-Hodgkin Lymphoma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4408-4408 ◽  
Author(s):  
Nobuhiko Nakamura ◽  
Takeshi Hara ◽  
Yuhei Shibata ◽  
Takuro Matsumoto ◽  
Ryoko Mabuchi ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Control Group ◽  
Rt Pcr ◽  
Treatment Groups ◽  
Model Mouse ◽  
Ifn Γ ◽  
The Mean ◽  
Cox 2

Background Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step in the catabolism of tryptophan along the kynurenine pathway. In tumors, increased IDO activity inhibits T cell and natural killer cell proliferation and induces apoptosis. We have previously reported that IDO expression in lymphoma cells and serum concentration of kynurenine in diffuse large B-cell lymphoma are useful prognostic factors. Preclinical studies in rodents have demonstrated that IDO inhibitors, such as 1-methyl-D-tryptophan (D-1MT), are therapeutically beneficial, especially when combined with different types of cytotoxic chemotherapeutic agents. We investigated the therapeutic potential of IDO inhibitor D-1MT with cyclophosphamide (CY) by using an IDO-positive B-cell lymphoma model mouse. Materials and Methods To establish tumors, 1x106 A20 cells (BALB/c B-cell lymphoma cell line) were subcutaneously injected into the lower back of naïve syngeneic BALB/c mice. Seven days later, 20 BALB/c mice were treated with D-1MT (Sigma-Aldrich, Saint Louis, MO, USA) and/or CY. The mice were fed with D-1MT-supplemented water (5mg/mL), which was replaced every two to three days. CY was administered at 80 mg/kg i.p. on day 10. To examine the effect of D-1MT on A20 tumors and tumor-draining lymph nodes (TDLNs), mice were sacrificed on day 28. Serum concentration of kynurenine and tryptophan were measured by high-performance liquid chromatography. CD4+CD25+Foxp3+ regulatory T cells (Tregs) were counted by flow cytometry with a FACSCantoII flow cytometer (BD Biosciences, San Jose, CA, USA), and data were analyzed with FACSDiva 6.1 software (BD Biosciences). Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed with specific primer/probe sets that amplify IDO1, Foxp3, IFN-γ, cyclooxygenase-2 (COX-2), and GAPDH genes (TaqMan Gene Expression Assays; Applied Biosystems, Foster City, CA). Results The mean body and spleen weights of the mice did not differ significantly among the groups. The mean drinking water intakes (mL/day/mouse) of the D-1MT, CY, and D-1MT+CY groups were significantly less than that of the control group (p< 0.05). All mice implanted with A20 cells developed tumors that became palpable after day 7. On day 28, the tumor volume in the D-1MT+CY group was significantly less than that in the control group (p< 0.05), and there were no significant differences among the other treatment groups (Figure 1). There were no significant differences in the serum kynurenine-to-tryptophan ratio and the IDO1 expression level in the tumors among any treatment groups. The expression levels of IFN-γ and COX-2 mRNA in TDLNs were found to be significantly up-regulated in the CY and D-1MT+CY groups. By quantitative RT-PCR, the expression levels of IFN-γ and COX-2 mRNA in TDLNs were found to be significantly up-regulated in the CY and D-1MT+CY groups. The Foxp3 expression level and number of Tregs in TDLNs in the CY and D-1MT+CY groups were significantly higher than in the control group on day 28. The number of Tregs in TDLNs in the D-1MT+CY group was significantly lower than those in CY groups on day 17 (p< 0.05) (Figure 2). Conclusion Our results suggest that D-1MT in combination with CY is an effective treatment for IDO-positive lymphoma in a model mouse by reducing Tregs and breaking tumor tolerance. This antitumor effect might be induced by the suppression of Tregs by D-1MT. Our findings suggest that inhibition of IDO might offer a promising treatment strategy for lymphoma. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Aldosterone stimulates superoxide production in macula densa cells

2011 ◽  
Vol 301 (3) ◽  
pp. F529-F535 ◽  
Author(s):  
Xiaolong Zhu ◽  
R. Davis Manning ◽  
Deyin Lu ◽  
Celso E. Gomez-Sanchez ◽  
Yiling Fu ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Western Blotting ◽  
Macula Densa ◽  
Tubuloglomerular Feedback ◽  
Epithelial Cell Line ◽  
Rt Pcr ◽  
Renal Epithelial Cell ◽  
Cyclooxygenase 1 ◽  
Cox 2 ◽  
Major Factors

Two major factors which regulate tubuloglomerular feedback (TGF)-mediated constriction of the afferent arteriole are release of superoxide (O2−) and nitric oxide (NO) by macula densa (MD) cells. MD O2− inactivates NO; however, among the factors that increase MD O2− release, the role of aldosterone is unclear. We hypothesize that aldosterone activates the mineralocorticoid receptor (MR) on MD cells, resulting in increased O2− production due to upregulation of cyclooxygenase-1 (COX-2) and NOX-2, and NOX-4, isoforms of NAD(P)H oxidase. Studies were performed on MMDD1 cells, a renal epithelial cell line with properties of MD cells. RT-PCR and Western blotting confirmed the expression of MR. Aldosterone (10−8 mol/l for 30 min) doubled MMDD1 cell O2− production, and this was completely blocked by MR inhibition with 10−5 mol/l eplerenone. RT-PCR, real-time PCR, and Western blotting demonstrated aldosterone-induced increases in COX-2, NOX-2, and NOX-4 expression. Inhibition of COX-2 (NS398), NADPH oxidase (apocynin), or a combination blocked aldosterone-induced O2− production to the same degree. These data suggest that aldosterone-stimulated MD O2− production is mediated by COX-2 and NADPH oxidase. Next, COX-2 small-interfering RNA (siRNA) specifically decreased COX-2 mRNA without affecting NOX-2 or NOX-4 mRNAs. In the presence of the COX-2 siRNA, the aldosterone-induced increases in COX-2, NOX-2, and NOX-4 mRNAs and O2− production were completely blocked, suggesting that COX-2 causes increased expression of NOX-2 and NOX-4. In conclusion 1) MD cells express MR; 2) aldosterone increases O2− production by activating MR; and 3) aldosterone stimulates COX-2, which further activates NOX-2 and NOX-4 and generates O2−. The resulting balance between O2− and NO in the MD is important in modulating TGF.

scholarly journals Anti-inflammatory steroid signalling in the human peritoneum

2007 ◽  
Vol 196 (2) ◽  
pp. 369-376 ◽  
Author(s):  
K S Fegan ◽  
M T Rae ◽  
H O D Critchley ◽  
S G Hillier
Keyword(s):  
Adhesion Formation ◽  
Premenopausal Women ◽  
Hydroxysteroid Dehydrogenase ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Peritoneal Surface ◽  
Interleukin 1Α ◽  
Cox 2 ◽  
Anti Inflammatory

Peritoneal surface epithelial (PSE) cells participate in adhesion formation following inflammatory injury yet adjacent ovarian SE (OSE) cells regenerate without scarification after ovulation. OSE cells show inflammation-associated expression of 11β hydroxysteroid dehydrogenase type 1 (11βHSD1) enzyme, enabling intracrine generation of anti-inflammatory cortisol to minimise tissue damage. We asked if human PSE cells show an 11βHSD1 response to pro-/anti-inflammatory stimulation and if so, how the 11-oxoreductase activity generated compares with OSE. PSE collected from premenopausal women undergoing surgery for benign gynaecological conditions were used to establish primary PSE cell cultures that were treated for 48 h with interleukin-1α (IL-1α) with/without anti-inflammatory steroid (cortisol or progesterone). mRNA levels corresponding to the genes of interest (11βHSD1, 11βHSD2, cyclooxygenase-2, COX-2) were measured by quantitative RT-PCR. IL-1α (0.5 ng/ml) stimulated 11βHSD1 and COX-2 mRNA levels in PSE cells but 11βHSD2 was unaffected. Cortisol (1 μM), not progesterone (1 μM), increased 11βHSD1 mRNA and synergistically enhanced IL-1α action. Cortisol suppressed IL-1α-stimulated COX-2 more effectively than progesterone. PSE cells had a significantly lower basal 11-oxoreductase enzyme activity than OSE cells; IL-1α did not significantly increase the 11-oxoreductase activity in PSE cells but did so in OSE cells. We conclude that PSE cells respond to IL-1α and anti-inflammatory steroids in qualitatively similar ways as OSE. However, the enzymatic activity of 11βHSD1 is lower in PSE and less responsive to IL-1α. This could help explain why peritoneal healing often leads to adhesion formation, whereas postovulatory ovarian healing is scar-free.

Erythropoietin (EPO) Is Proved to Have a Very Important Role in the Expression of Cyclooxygenase-2 (COX-2) and Cytochrome-c (CYT-c) in the Bleomycin (BLM)-Induced Pulmonary Fibrosis (PF) in Rat

CHEST Journal ◽  
2011 ◽  
Vol 140 (4) ◽  
pp. 587A
Author(s):  
Drosos Tsavlis ◽  
Anna Tzoumaka ◽  
Georgia Kokaraki ◽  
Kokona Kouzi-Koliakos ◽  
Anastasia Tektonidou ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Pulmonary Fibrosis ◽  
Cyclooxygenase 2 ◽  
Cyt C ◽  
Cox 2

Expression of proteinase-activated receptor 2 on human primary gastrointestinal myofibroblasts and stimulation of prostaglandin synthesis

2005 ◽  
Vol 83 (7) ◽  
pp. 605-616 ◽  
Author(s):  
Michelle L Seymour ◽  
David G Binion ◽  
Steven J Compton ◽  
Morley D Hollenberg ◽  
Wallace K MacNaughton
Keyword(s):  
Small Intestine ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Rt Pcr ◽  
Concentration Dependent Manner ◽  
Cell Functions ◽  
Cox 2 ◽  
Colonic Cells ◽  
Cox 1 ◽  
Stimulation Of

It is known that subepithelial myofibroblast-derived prostaglandin (PG)E2 can regulate intestinal epithelial cell functions, and that proteinase-activated receptor-2 (PAR2) is abundantly expressed in the gastrointestinal tract. Since PAR2 activation has previously been associated with stimulation of PGE2 synthesis, we hypothesized that PAR2 expressed on primary human gastrointestinal myofibroblasts regulates PGE2 synthesis via cyclooxygenase (COX)-1 and (or) COX-2, and associated PGE synthases. Primary human myofibroblasts were isolated from the resection tissue of the esophagus, small intestine, and colon. Expression of functional PAR2 was determined by RT-PCR and by calcium mobilization in Fura-2/AM-loaded cells. Trypsin and the selective PAR2-activating peptide (PAR2-AP) SLIGRL-NH2 stimulated PGE2 synthesis in a concentration-dependent manner, as measured by enzyme immunoassay. Selective COX inhibition showed PAR2-induced PGE2 synthesis to be COX-1 dependent in esophageal myofibroblasts and both COX-1 and COX-2 dependent in colonic cells, consistent with the distribution of COX-1 and COX-2 expression. Although both cytosolic and microsomal PGE synthases were expressed in cells from all tissues, microsomal PGE synthases were expressed at highest levels in the colonic myofibroblasts. Activation of PAR2 on gastrointestinal myofibroblasts stimulates PGE2 synthesis via different pathways in the colon than in the esophagus and small intestine. Key words: Proteinase-activated receptor, myofibroblast, cyclooxygenase, PGE synthase, prostaglandin E2, esophagus, small intestine, colon.

Histamine-dependent prolongation by aldosterone of vasoconstriction in isolated small mesenteric arteries of the mouse

2013 ◽  
Vol 304 (8) ◽  
pp. H1094-H1102 ◽  
Author(s):  
Jeppe Schjerning ◽  
Torben R. Uhrenholt ◽  
Per Svenningsen ◽  
Paul M. Vanhoutte ◽  
Ole Skøtt ◽  
...  
Keyword(s):  
Mast Cells ◽  
Receptor Antagonist ◽  
Vascular Function ◽  
Mesenteric Arteries ◽  
Wild Type ◽  
Rt Pcr ◽  
No Donor ◽  
High K ◽  
Cox 2 ◽  
Cox 1

In arterioles, aldosterone counteracts the rapid dilatation (recovery) following depolarization-induced contraction. The hypothesis was tested that this effect of aldosterone depends on cyclooxygenase (COX)-derived products and/or nitric oxide (NO) synthase (NOS) inhibition. Recovery of the response to high K+ was observed in mesenteric arteries of wild-type and COX-2−/− mice but it was significantly diminished in preparations from endothelial NOS (eNOS)−/− mice. Aldosterone pretreatment inhibited recovery from wild-type and COX-2−/− mice. The NO donor sodium nitroprusside (SNP) restored recovery in arteries from eNOS−/− mice, and this was inhibited by aldosterone. Actinomycin-D abolished the effect of aldosterone, indicating a genomic effect. The effect was blocked by indomethacin and by the COX-1 inhibitor valeryl salicylate but not by NS-398 (10−6 mol/l) or the TP-receptor antagonist S18886 (10−7 mol/l). The effect of aldosterone on recovery in arteries from wild-type mice and the SNP-mediated dilatation in arteries from eNOS−/− mice was inhibited by the histamine H2 receptor antagonist cimetidine. RT-PCR showed expression of mast cell markers in mouse mesenteric arteries. The adventitia displayed granular cells positive for toluidine blue vital stain. Confocal microscopy of live mast cells showed loss of quinacrine fluorescence and swelling after aldosterone treatment, indicating degranulation. RT-PCR showed expression of mineralocorticoid receptors in mesenteric arteries and in isolated mast cells. These findings suggest that aldosterone inhibits recovery by stimulation of histamine release from mast cells along mesenteric arteries. The resulting activation of H2 receptors decreases the sensitivity to NO of vascular smooth muscle cells. Aldosterone may chronically affect vascular function through paracrine release of histamine.

Effects of Celecoxib on Human Acute Promyelocytic Leukemia Cell Line and Its Mechanism.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2851-2851
Author(s):  
Yun Xu ◽  
He Huang ◽  
Yanmin Zhao ◽  
Fenfang Zeng ◽  
Qian Zhou
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Fusion Gene ◽  
Telomerase Activity ◽  
Promyelocytic Leukemia ◽  
Time Dependent ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Cycle Arrest ◽  
Cox 2

Abstract Acute promyelocytic leukemia (APL) is a special subtype of acute myelogenous leukemia (AML) which is characterized for a specific translocation between chromosome 15 and 17 [t(15;17)] and the expression of PML/RARα fusion gene. Celecoxib, one of the specific inhibitors of cyclooxygenase-2 (COX-2), has been reported to induce anti-neoplastic activity on many solid human tumor cell lines in recent years. In our study, ATRA resistant APL cell line MR2 cells were used to investigate the effects of celecoxib on hematological malignancy. MR2 cells were treated with celecoxib at different concentration (0, 20, 40, 80, 120 and 160μmol/L). The proliferation of MR2 cells was observed by MTT assay and apoptosis was detected by DNA fragmentation analysis and flow cytometry using Annexin V-FITC/PI staining. Western blot was used to detect the change of caspase-8, -9, -3 and PARP in MR2 cells. The expression of mRNA of fusion gene PML/RARα, COX-2 and survivin, bcl-2/bax, CIAP1 and CIAP2 was assessed by reverse transcription polymerase chain reaction (RT-PCR). Cell cycle analyzed by flow cytometry with PI staining and western blot was used to detect the expression of cell-cycle-regulating proteins. The telomerase activity of MR2 cells was analyzed by PCR-ELISA. The expression of hTERT mRNA and c-myc mRNA was assessed by RT-PCR. MR2 cells viability in presence of celecoxib decreased markedly in a dose- and time- dependent manner. After treated with celecoxib (20-160μmol/L) for 12-48h, the proliferation of MR2 cells were inhibited significantly, in comparison with the control group (P<0.01). 50% growth inhibition (IC50) at 24h and 48h was 80.93μmol/L and 71.72μmol/L, respectively. A DNA ladder pattern of internucleosomal fragmentation was observed. The translocation of phosphatidylserine at the outer surface of the cell plasma membrane could be induced by celecoxib and its level increased following the augmentation of the drug concentration. MR2 cells exposure to 40-160μmol/L celecoxib for 24h caused 9.59%, 24.00%, 36.10% apoptotic cells, which was more than that of the untreated group 2.84% (P<0.01). The expression of survivin mRNA decreased dramatically, while no significant change with PML/RARα and COX-2. Treatment with celecoxib for 24h resulted in the activation of caspase-3 and caspase-9, cleavage of PARP. 40-160μmol/L celecoxib led to cell cycle arrest in G1/S phase, and CyclinD1 and CyclinE decreased, accompanied with up-regulation of P21waf/cip1, P27KIP, P16INK4a. celecoxib could inhibit the telomerase activity of APL cell line, and the inhibition was dose- and time- dependent. The expression of hTERT mRNA and c-myc mRNA were down-regulated by celecoxib in dose- dependent manner. These results indicated that celecoxib could inhibit MR2 cells proliferation by inducing apoptosis, cell cycle arrest and suppression of telomerase activity.

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